3D and Multi Object Spectroscopy

3D, also called integral-field spectroscopy (IFS), is an approach that allows astronomers to obtain spectra for each point across an image produced by a telescope. The AIP uses and actively develops this complex technology, including, with a particular emphasis on fibre-optics, the design and manufacture of new instrumentation, the development of 3D data reduction, analysis and visualisation software, and finally scientific research using 3D-or integral-field spectroscopic techniques.

The AIP is involved in the development of the two largest 3D spectrographs of their kind – MUSE for the European Southern Observatory (ESO) in Chile, and VIRUS for the McDonald Observatory in Texas. These developments are based on twelve years of expe­rience with the AIP-built PMAS instrument that operates at the Calar Alto Observatory in Spain. Future 3D instrument concepts are being studied, ranging from single-field to deployable multiple-field spectrographs.

A major topic is the development of data reduction and visualization software for 3D-spectroscopy. The data reduction pipeline for the MUSE instrument can handle 90,000 spectra in one exposure and re-constructs images of the astronomical targets from these. The AIP-developed p3d-software is used worldwide to reduce astronomical spectra from fibre-based multi-channel spectrographs.

Multi-Object Spectroscopy (MOS) allows the observer to select many astronomical objects within the available field-of-view of the instrument, to obtain all these spectra in a single exposure. Technologically, this is usually done with placing fibre-optics at the location of the images of stars and galaxies within the telescope focal plane. AIP leads the RAVE survey that has obtained 500,000 stellar spectra of the Milky Way and provided replacement fibre-optics for the 6dF instrument at the AAO.

AIP is the leading institute of an international consortium that has provided an accepted concept study for a Multi-Object Spectroscopic Telescope facility, called 4MOST, for the 4m VISTA telescope at ESO's Paranal Observatory.